1. Field of the Invention
The present invention relates to an electronic appliance with a video camera, such as a television set, and particularly, to an electronic appliance with a video camera that recognizes a motion in images of, for example, a human hand and remotely controls an electronic appliance according to the recognized motion.
2. Description of Related Art
In the 1980s, infrared remote controllers started to be attached to home appliances such as television sets. The remote control user interfaces have widely spread and greatly changed the usage of home appliances. At present, the operation with remote controllers is in the mainstream. The remote controller basically employs a one-push, one-function operation. A television remote controller, for example, has ON/OFF, CHANNEL, VOLUME, and INPUT SELECT keys for conducting respective functions. The remote controllers are very useful for remotely controlling the television set and electronic devices connected to the television set.
When the remote controller is not present nearby, or when it is unclear where the remote controller is, the user experiences dreadful inconvenience. To cope with this, a method is studied that recognizes the motion and shape of an objective image, and according to a result of recognition, conducts an operation such as a power ON/OFF operation. A technique of recognizing the motion and shape of a hand and operating an appliance according to a result of recognition is disclosed in Japanese Unexamined Patent Application Publication No. Hei11(1999)-338614. To detect the motion and shape of a hand, the disclosure employs a dedicated infrared sensor and a special image sensor.
Data broadcasting that has started recently requires UP, DOWN, LEFT, RIGHT, and OK keys of a remote controller to be pushed several times to display a required menu. This is troublesome for the user. An EPG (electronic program guide) displays a matrix of guides and prompts the user to select a desired one of the guides by pushing keys on a remote controller. This is also troublesome for the user. For such a detailed selection operation, there is a need for a method that can recognize the motion and shape of an objective image and conduct a control operation accordingly.
A solution disclosed in Japanese Unexamined Patent Application Publication No. 2003-283866 is a controller that obtains positional information with a pointing device such as a mouse, encodes the positional information into a time-series code string which is a time-series pattern of codes representative of pushed keys, and transmits the time-series code string to a television set.
Home AV appliances such as audio units, video devices, and television sets realize remote control with use of remote controllers. If a remote controller is not present nearby, the user must find the remote controller, pick up it, and selectively manipulate keys on the remote controller to, for example, turn on the home appliance. These actions are inconvenient for the user to take. If the remote controller is unfound, the user must turn on the appliance by manipulating a main power switch on the appliance itself. This is the problem frequently experienced with the remote controller.
An operation of turning off the appliance can smoothly be carried out if the remote controller is in the user's hand. If, however, the remote controller is not in the user's hand, the user must feel inconvenience.
The control method disclosed in the Japanese Unexamined Patent Application Publication No. Hei11(1999)-338614 employs motions such as a circular motion, vertical motion, and horizontal motion. These motions are simple, and therefore, the method will be easy to use for a user if images of the motions are correctly recognized. The simple motions, however, involve erroneous recognition, increase apparatus size for achieving motion recognition, and need a special recognition device that is incompatible with other image recognition devices.
The controller disclosed in the Japanese Unexamined Patent Application Publication No. 2003-283866 allows a user to conduct a pointing operation similar to that of a personal computer and remotely control a television set. This controller, therefore, is inconvenient for a person who is unfamiliar with the operation of a personal computer. From the view point of information literacy (ability of utilizing information), the related art is somewhat unreasonable because it forcibly introduces the handling scheme of personal computers into the handling scheme of home appliances such as television sets. A need exists in a new remote control method appropriate for television sets.
To provide inexpensive home appliances, there is a need of a control unit that can be materialized in a proper size and can achieve an image recognition for a two-alternative selection operation such as a power ON/OFF operation and an image recognition for a multiple selection operation such as one carried out on a menu screen. An image recognition of a simple motion easily causes an erroneous recognition. Such an erroneous recognition will cause a critical error such as turning off a television set while a user is watching the same, and therefore, must be avoided.